test: remove material-design-icons package E2E test

The `material-design-icons` package has not been updated in 5 years and is a large package (40+MB) that frequently causes CI flakes. The recommended method to including the Material design icons is with the Google Fonts API via a index HTML link element (allows for font inlining during production builds). As a result, this test has now been removed.

Author: clydin